--
-- Copyright (C) 2016-2017 secunet Security Networks AG
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 2 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--

with HW.GFX.GMA.Config;
with HW.GFX.GMA.Registers;
with HW.GFX.GMA.Config_Helpers;

package body HW.GFX.GMA.Port_Detect
is

   DDI_BUF_CTL_A_LANE_CAPABILITY_X4    : constant := 1 * 2 **  4;

   SFUSE_STRAP_CRT_DAC_CAP_DISABLE     : constant := 1 * 2 **  6;

   HOTPLUG_CTL_DDI_A_HPD_INPUT_ENABLE  : constant := 1 * 2 **  4;
   HOTPLUG_CTL_DDI_A_HPD_STATUS        : constant := 3 * 2 **  0;
   HOTPLUG_CTL_DDI_A_HPD_LONG_DETECT   : constant := 1 * 2 **  1;

   SHOTPLUG_CTL_DETECT_MASK            : constant := 16#0303_0303#;

   type Digital_Port_Value is array (Digital_Port) of Word32;
   DDI_PORT_DETECTED : constant Digital_Port_Value :=
     (DIGI_B => 1 * 2 **  2,
      DIGI_C => 1 * 2 **  1,
      DIGI_D => 1 * 2 **  0,
      DIGI_A => 1 * 2 **  0,
      others => 0);
   SHOTPLUG_CTL_HPD_INPUT_ENABLE : constant Digital_Port_Value :=
     (DIGI_B => 1 * 2 **  4,
      DIGI_C => 1 * 2 ** 12,
      DIGI_D => 1 * 2 ** 20,
      DIGI_A => 1 * 2 ** 28,
      others => 0);
   SHOTPLUG_CTL_HPD_STATUS : constant Digital_Port_Value :=
     (DIGI_B => 3 * 2 **  0,
      DIGI_C => 3 * 2 **  8,
      DIGI_D => 3 * 2 ** 16,
      DIGI_A => 3 * 2 ** 24,
      others => 0);
   SHOTPLUG_CTL_LONG_DETECT : constant Digital_Port_Value :=
     (DIGI_B => 1 * 2 **  1,
      DIGI_C => 1 * 2 **  9,
      DIGI_D => 1 * 2 ** 17,
      DIGI_A => 1 * 2 ** 25,
      others => 0);

   procedure Initialize
   is
      DDI_A_X4,
      DAC_Disabled,
      Internal_Detected,
      DDI_Detected : Boolean;

      subtype Ext_Digital_Port is
         Digital_Port range DIGI_B .. DIGI_D;
      type Digital_Port_To_GMA_Port is array (Ext_Digital_Port) of Port_Type;
      To_HDMI_Port : constant Digital_Port_To_GMA_Port :=
        (DIGI_B => HDMI1,
         DIGI_C => HDMI2,
         DIGI_D => HDMI3);
      To_DP_Port : constant Digital_Port_To_GMA_Port :=
        (DIGI_B => DP1,
         DIGI_C => DP2,
         DIGI_D => DP3);
   begin
      if Config.Has_DDI_E and Config.Has_PCH_DAC then
         -- PCH_DAC (_A)
         Registers.Is_Set_Mask
           (Register => Registers.DDI_BUF_CTL_A,
            Mask     => DDI_BUF_CTL_A_LANE_CAPABILITY_X4,
            Result   => DDI_A_X4);
         Registers.Is_Set_Mask
           (Register => Registers.SFUSE_STRAP,
            Mask     => SFUSE_STRAP_CRT_DAC_CAP_DISABLE,
            Result   => DAC_Disabled);
         Config.Valid_Port (Analog) := not (DDI_A_X4 or DAC_Disabled);
      end if;

      -- DDI_A
      if Config.Has_Presence_Straps then
         Registers.Is_Set_Mask
           (Register => Registers.DDI_BUF_CTL_A,
            Mask     => DDI_PORT_DETECTED (DIGI_A),
            Result   => Internal_Detected);
      else
         Internal_Detected := True; -- XXX: Linux' i915 contains a fixme.
      end if;
      if Internal_Detected then
         if Config.Has_HOTPLUG_CTL then
            Registers.Set_Mask
              (Register => Registers.HOTPLUG_CTL,
               Mask     => HOTPLUG_CTL_DDI_A_HPD_INPUT_ENABLE or
                           HOTPLUG_CTL_DDI_A_HPD_STATUS);   -- clear status
            if Config.Has_SHOTPLUG_CTL_A then
               -- Have to enable south hotplug too on SoCs.
               Registers.Unset_And_Set_Mask
                 (Register    => Registers.SHOTPLUG_CTL,
                  Mask_Unset  => SHOTPLUG_CTL_DETECT_MASK,
                  Mask_Set    => SHOTPLUG_CTL_HPD_INPUT_ENABLE (DIGI_A));
            end if;
         else
            Registers.Unset_And_Set_Mask
              (Register    => Registers.SHOTPLUG_CTL,
               Mask_Unset  => SHOTPLUG_CTL_DETECT_MASK,
               Mask_Set    => SHOTPLUG_CTL_HPD_INPUT_ENABLE (DIGI_A) or
                              SHOTPLUG_CTL_HPD_STATUS (DIGI_A));  -- clear
         end if;
      end if;
      Config.Valid_Port (eDP) := Internal_Detected;

      -- DDI_[BCD]
      for Port in Ext_Digital_Port range
         DIGI_B .. Ext_Digital_Port'Min (DIGI_D, Config.Last_Digital_Port)
      loop
         if Config.Has_Presence_Straps then
            Registers.Is_Set_Mask
              (Register => Registers.SFUSE_STRAP,
               Mask     => DDI_PORT_DETECTED (Port),
               Result   => DDI_Detected);
         else
            DDI_Detected := True;
         end if;
         Config.Valid_Port (To_HDMI_Port (Port)) := DDI_Detected;
         Config.Valid_Port (To_DP_Port (Port)) := DDI_Detected;

         if DDI_Detected then
            Registers.Unset_And_Set_Mask
              (Register    => Registers.SHOTPLUG_CTL,
               Mask_Unset  => SHOTPLUG_CTL_DETECT_MASK,
               Mask_Set    => SHOTPLUG_CTL_HPD_INPUT_ENABLE (Port) or
                              SHOTPLUG_CTL_HPD_STATUS (Port)); -- clear status
         else
            Registers.Unset_Mask
              (Register => Registers.SHOTPLUG_CTL,
               Mask     => SHOTPLUG_CTL_DETECT_MASK or
                           SHOTPLUG_CTL_HPD_INPUT_ENABLE (Port));
         end if;
      end loop;
   end Initialize;

   procedure Hotplug_Detect (Port : in Active_Port_Type; Detected : out Boolean)
   is
      Ctl32 : Word32;
      GPU_Port : constant GMA.GPU_Port :=
         Config_Helpers.To_GPU_Port (Primary, Port);
   begin
      if Config.Has_HOTPLUG_CTL and then GPU_Port = DIGI_A then
         Registers.Read (Registers.HOTPLUG_CTL, Ctl32, Verbose => False);
         Detected := (Ctl32 and HOTPLUG_CTL_DDI_A_HPD_LONG_DETECT) /= 0;

         if (Ctl32 and HOTPLUG_CTL_DDI_A_HPD_STATUS) /= 0 then
            Registers.Set_Mask
              (Register => Registers.HOTPLUG_CTL,
               Mask     => HOTPLUG_CTL_DDI_A_HPD_STATUS);
         end if;
      elsif GPU_Port in DIGI_A .. DIGI_D then
         Registers.Read (Registers.SHOTPLUG_CTL, Ctl32, Verbose => False);
         Detected := (Ctl32 and SHOTPLUG_CTL_LONG_DETECT (GPU_Port)) /= 0;

         if (Ctl32 and SHOTPLUG_CTL_HPD_STATUS (GPU_Port)) /= 0 then
            Registers.Unset_And_Set_Mask
              (Register    => Registers.SHOTPLUG_CTL,
               Mask_Unset  => SHOTPLUG_CTL_DETECT_MASK,
               Mask_Set    => SHOTPLUG_CTL_HPD_STATUS (GPU_Port));
         end if;
      else
         Detected := False;
      end if;
   end Hotplug_Detect;

   procedure Clear_Hotplug_Detect (Port : Active_Port_Type)
   is
      Ignored_HPD : Boolean;
   begin
      pragma Warnings (GNATprove, Off, "unused assignment to ""Ignored_HPD""",
                       Reason => "We want to clear pending events only");
      Port_Detect.Hotplug_Detect (Port, Ignored_HPD);
      pragma Warnings (GNATprove, On, "unused assignment to ""Ignored_HPD""");
   end Clear_Hotplug_Detect;

end HW.GFX.GMA.Port_Detect;